Hey guys looking for some input on this type of suspension setup. I saw this truck for sale on FB, and the owner doesn't know anything about the setup. I've seen this done a couple other times a few different ways. I would like to do something similar, as I'm not crazy about radius rods. So was wondering if anybody has done a setup like this, what's it even called, how does it ride, and so forth. Thanks for any input.
Willy it's not 1/4 elliptical the spring is in front of the axle. I'm more referring to the square tubes being used in place of radius rods.
What you have in these pictures is functionally a forward facing swingarm. It will have little to no articulation.
What an abomination! Are those giant tubes on the back to hold brooms so you can sweep up the wreckage when it understeers into a kerb??!!
It's still radius rods, just square tube instead of hairpins or split wishbone. Looks like a parallel leaf axle, so tube was the easiest thing to attach.
Pretty much like the typical I-beam/split wishbone front suspension other than the truck axle won't flex as easily as a regular early Ford axle; so I would say it would ride a little tougher on uneven roads. The big square wishbones are functional; but pretty clunky. I would look real close at the welding on that rig anywhere changes were made or components fabricated.
What it looks like to me is that the previous owner is using the spring mounts on an axle that was set up as a parallel sprung axle as the radius rod attachment points. If you are happy with the setup you can always "clean it up" with different ways to attach wishbones or a split wishbone setup. Can we get more pictures?
Those two “radius rods”are u-bolted solidly onto the axle close together. For one wheel to rise while the other stays put, that fat axle has to twist. That big axle, in that short section, isn’t going to want to twist. Basically it’s like parallel ladder bars on a rear end, it’ll go down the road but eventually something’s gonna crack or break. It’s definitely not a design that I would copy for my car.
I'm not looking to purchase this truck. I'm getting ready to start my own build. Just asking about the suspension. Thanks
Not a good design. It will bounce but it can't articulate side to side. Hit a pavement situation where one front wheel wants to dip or rise relative to the opposite wheel and it can't do it. Both wheels must go up and down together. This will put undue twisting stress on the frame and radius arms and over time, something will break.
Sure; but look around for suspension ideas built around prewar Ford transverse spring axles & wishbones for a win. Seems like a easy idea to pick-up a '50s truck axle ready to go with good brakes and all; but pretty soon ugly rears it head trying to set up a cross-spring and wishbone off the spring saddles on the axle and still have it look like something.
Can't do wishbones, as I have a 56 F100 axle was just looking for something different than hairpins. To me they don't look right on a pickup. Might just have to design my own radius rods.
I had to play with the pictures to see anything...I'm too old for phone pictures, apparently. Axles that were designed to work with parallel leaf springs, work pretty well with parallel leaf springs. If you want to use a traditional cross leaf spring like an early Ford, then use the right axle, with radius rods or 4 bar. Proven over the decades to work well.
FYI the brakes on you '56 F-100 axle work pretty good on a normal hot rod suspension. Even Rudy's truck that started it used an early Ford beam axle front end.
It's not quite as bad as the ugly would suggest, but I do see a few issues. As others have pointed out, the axle may be too heavy to accommodate the torsional flexing this kind of location requires without adding a lot of (unconsidered but not necessarily bad) roll stiffness to the front end. If this is the case there will be a bending moment in the square-tube arms, and they aren't very deep. There will be two stress risers just aft of the attachment to the axle, and hence two potential failure points. Would cross-drilling the middle part of the axle rather liberally reduce its torsional stiffness enough to make it work? Lateral location seems to be by the spring shackles only. I can't see anything to suggest that bump steer was considered at all in the steering linkage. It might be a case of "any suspension can work if you don't let it," but the transverse leaf seems rather light for that.
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